GB956735A - Pipe coupling - Google Patents

Abstract

956,735. Pipe couplings. FMC CORPORATION. May 8, 1962 [July 13, 1961], No. 17581/62. Heading F2G. A pipe coupling 10 comprises a first 11 and second 12 coupling members locked together and a sealing ring 22 located in an annular, elliptical cross-sectioned chamber 21 formed by co-operating annular grooves 19, 20 in the coupling members. A fluid-pressure differential across the pipe and hence across chamber 21 increases the effectiveness of the sealing by forcing ring 22 towards the end of the major axis of the elliptical cross-section. Further co-operating annular grooves 23, 24 are provided in members 11, 12 into which keeper balls 25 are introduced through an access port 26 to prevent relative axial movement of the members. Relative rotation is prevented by a continuous or broken weld 27. In modifications (Figs. 2, 3, 4, 5, not shown), two sets of co-operating annular grooves housing keeper balls are provided. The access ports are circumferentially spaced, tapped and provided with grub screws the inner ends of which are formed to co-operate either with the bottom of the grooves (Fig. 2), with keeper balls (Fig. 3), or with large locking balls which deform the edges of their respective grooves (Fig. 5, not shown), to prevent relative rotation. In the construction shown in Fig. 6 the keeper balls 105 are held in the annular grooves 103 by cover plates 107 and snap rings 108 housed in access ports 106. Relative rotation is prevented by an arcuate spring steel rod or wire 104 held in an arcuate groove machined between the access ports 106 and in the outer surface of coupling member 93. In a further embodiment (Fig. 7), a grub screw 115 prevents the relative rotation and relative axial movement is limited by a longitudinally split sleeve 116, flanges 117, 118 of which co-operate with grooves 119, 120 in the two coupling members 111, 112 respectively. The parts of sleeve 116 are retained by a sleeve member 121 and snap ring 123. In the construction shown in Fig. 9, the two annular grooves are provided with cylindrical elements 137 which are locked in place by retainers 141 housed in the access ports and a single cover 142 held by a screw 143, the screw co-operating with the coupling members to prevent relative rotation. The sealing rings 22 may possess a circular or generally elliptical cross-section, the cross-sectional area being greater than that of the annular sealing chamber 21.